INGREDIENTS
3/4 cup
unsalted butter (room temperature)
1 cup
brown sugar
1/2 cup
granulated sugar
1
egg (room temperature)
1 tbsp
vanilla extract
2 1/2 cups
all-purpose flour
2 tsp
cornstarch
1 tsp
baking soda
1/2 tsp
salt
12 oz
semi-sweet chocolate chips
1 cup
M&Ms ( plus more to top the cookie if desired)